Question

Please help me with this question​

Answer 1

Answer:5km/hr

Step-by-step explanation:

Answer 2

Answer:

Step-by-step explanation:

take speed of stream as x kmph

given that speed of boat is 15 kmph

we also have the time and distance in our hands, and according to question  going upstream [its (15-y) since stream flows downstream] and returning back downstream(15+y) to same point takes 4hrs and 30mins==>9/2hrs

so equation is 30/15+x +30/15-x = 9/2 hrs

==>30 {15-x+15+x/225-x²}=9/2     ........taking L.C.M

==>30×30×2/9=225-x²

==>100×2=225-x²

==>x²=25

==>x=±5  .......speed can't be negative so x=5 kmph

hope it helps!